This invention relates to a technique for conferencing arrangements and, in particular, to a technique for a conferencing arrangement for use with two or more wireless terminals.
Conferencing is the ability to couple information signals among three or more users in a communication system. The conferencing arrangement may involve voice or non-voice signals, including data, video, and facsimile signals.
In the case of audio teleconferencing, there may be one or more wireless users involved in the communication. Typically, in digital wireless systems speech is transmitted over the air interface as packets or frames. Accordingly, the incoming speech at a subscriber terminal is collected, organized into frames and low bit rate encoded. The speech is then transcoded to pulse code modulated speech (PCM) before entering the mobile switching center (MSC). Then generally, in the case where a voice conferencing bridge is involved, the signal power of the conferees is measured, compared, and each conferee receives a weighted sum of perhaps the two loudest talkers other than him/herself. For conference calls involving two or more wireless participants, the signals received by the wireless terminals will be transcoded to linear PCM, a weighted sum will be taken and then reencoding will take place, even when only a single participant in the conference is speaking. Such a tandem-encoded signal will demonstrate degraded quality of voice.
There was an attempt made in the prior art by D. Nahumi in U.S. Pat. No. 5,390,177 to improve the voice quality in a conference bridge. In the Nahumi patent, the conferencing bridging technique is for use with compressed information signals only. The technique involves first measuring the signal energy transmitted by each conferee. When there is only one conferee speaking, the summing circuit and the speech decoding/coding apparatus is bypassed, and the talking conferee""s signal is broadcast to all conferees. When there is more than one conferee speaking at a given time, then only the speaking conferees"" signals are routed to an associated speech decoder wherein those conferees"" compressed signals are decompressed. The summing circuit then combines these decompressed signals and the sum is recompressed and broadcast to all conferees. The invention disclosed in the Nahumi patent does not have the capability to provide more than one output signal, as the conference bridge has only a single speech encoder in the output direction. Thus, the same compressed signal is broadcast to all users.
There exists therefore a need for a telephone conferencing arrangement in the situation where there are two or more wireless users, and there may or may not be PSTN users whose signals may or may not be compressed, which would provide clearer communication than that associated with prior conferencing arrangements and in which there is the capability to provide more than one output signal. There is a need for a system in which the conference bridge would result in superior signal addition and performance.
An object of the present invention is to provide an improved telephone conferencing arrangement for use with two or more wireless terminals, and any or no PSTN terminals.
In accordance with an aspect of the present invention, there is provided a conferencing apparatus comprising means for receiving signals at a conference bridge from a plurality of input communication paths of which at least two are associated with low bit rate voice signals, means for estimating the signal energy in each of said input communication paths to give a signal energy estimation, means for comparing each of said signal energy estimations against a predetermined threshold, and means responsive to said signal energy estimating and comparing means for forwarding the low bit rate voice signal from one of said input communication paths to a second output communication path also associated with an incoming low bit rate voice signal, when said signal energy estimation provides a first result.
In accordance with another aspect of the present invention, there is provided a conferencing apparatus comprising means for receiving signals at a conference bridge from a plurality of input communication paths of which at least two are associated with low bit rate voice signals, means for estimating the signal energy in each of said input communication paths to give a signal energy estimation, means for comparing each of said signal energy estimations against a predetermined threshold, and means responsive to said signal energy estimating and comparing means for forwarding the low bit rate voice signal from one of said input communication paths to one or more output communication paths, each associated with an incoming low bit rate voice signal, if the signal energy estimation of only said one of said input communication paths is above said predetermined threshold.
In accordance with a further aspect of the present invention, there is provided a conferencing apparatus comprising means for receiving signals at a conference bridge from a plurality of input communication paths of which at least two are associated with low bit rate voice signals, means for estimating the signal energy in each of said input communication paths to give a signal energy estimation, means for comparing each of said signal energy estimations against a predetermined threshold, and means responsive to said signal energy estimating and comparing means for forwarding a first low bit rate voce signal and a second low bit rate voice signal from each of two input communication paths to output communication paths associated with said two input communication paths, wherein said first low bit rate voice signal is forwarded to the output communication path associated with the second low bit rate voice signal and vice versa, when said signal energy estimating and comparing means provides a second result.
In a still further aspect of the invention, there is provided a conferencing apparatus comprising means for receiving signals at a conference bridge from a plurality of input communication paths of which at least two are associated with low bit rate voice signals, means for estimating the signal energy in each of said input communication paths to give a signal energy estimation, means for comparing each of said signal energy estimations against a predetermined threshold, and means responsive to said signal energy estimating and comparing means for decoding only each of said low bit rate voice signals that is required by said conferencing apparatus.
In a yet further aspect of the invention, there is provided a method of providing a conference communication comprising the steps of receiving signals at a conference bridge from a plurality of input communication paths of which at least two are associated with low bit rate voice signals, estimating the signal energy in each of said input communication paths to obtain a signal energy estimation, comparing each of said signal energy estimations against a predetermined threshold to obtain a signal energy comparison, and in response to said signal energy estimations and comparisons, forwarding the low bit rate voice signal from one of said input communication paths to a second output communication path also associated with an incoming low bit rate voice signal, when said signal energy estimation provides a first result.
In another aspect of the invention, there is provided a method of providing a conference communication comprising the steps of receiving signals at a conference bridge from a plurality of input communication paths of which at least two are associated with low bit rate voice signals, estimating the signal energy in each of said input communication paths to obtain a signal energy estimation, comparing each of said signal energy estimations against a predetermined threshold to obtain a signal energy comparison, and in response to said signal energy estimations and comparisons, forwarding the low bit rate voice signal from one of said input communication paths to one or more output communication paths, each associated with an incoming low bit rate voice signal, if the signal energy estimation of only said one of said input communication paths is above said predetermined threshold.
In a still further aspect of the invention, there is provided a method of providing a conference communication comprising the steps of receiving signals at a conference bridge from a plurality of input communication paths of which at least two are associated with low bit rate voice signals, estimating the signal energy in each of said input communication paths to obtain a signal energy estimation, comparing each of said signal energy estimations against a predetermined threshold to obtain a signal energy comparison, and in response to said signal energy estimations and comparisons, forwarding a first low bit rate voce signal and a second low bit rate voice signal from each of two input communication paths to output communication paths associated with said two input communication paths, wherein said first low bit rate voice signal is forwarded to the output communication path associated with the second low bit rate voice signal and vice versa, when said signal energy estimation and comparison provides a second result.
In a yet further aspect of the invention, there is provided a method of providing a conference communication comprising the steps of receiving signals at a conference bridge from a plurality of input communication paths of which at least two are associated with low bit rate voice signals, estimating the signal energy in each of said input communication paths to obtain a signal energy estimation, comparing each of said signal energy estimations against a predetermined threshold to obtain a signal energy comparison, and in response to said signal energy estimations and comparisons, decoding only each of said low bit rate voice signals that is required for said conference communication.